Oil formulation for preventing water penetration in underground formations

Abstract

The present invention relates to the use of an oil formulation in the field of the oil industry, in particular for the prevention of water penetration. The formulation according to the invention is in particular intended to be injected into underground formations, such as injection wells or production wells.

1 . A liquid oil formulation comprising:
 (a) a compound comprising at least two isocyanate functional groups;   (b) a surfactant; and   (c) an aromatic oil capable of dissolving compounds (a) and (b).   
     
     
         2 . The formulation of  claim 1 , wherein compound (a) is isophorone diisocyanate, toluene diisocyanate, biphenyl diisocyanate, dimethoxy-4,4′-biphenyl diisocynate, dimethyl-4,4′-biphenyl diisocyanate, 1,3-bis (isocyanatomethyl) benzene, phenyl diisocyanate, tolylene diisocyanate, diisocynatohexane, diisocyanatooctane, diisocyanatobutane, xylene diisocyanate, octamethylene diisocyanate, or phenylene diisocyanate. 
     
     
         3 . The formulation of  claim 1 , wherein compound (a) is a diisocyanate polymer. 
     
     
         4 . The formulation of  claim 1 , wherein the concentration of compound (a) ranges from 1 to 15% by weight. 
     
     
         5 . The formulation of  claim 1 , wherein the surfactant (b) comprises:
 fatty acids;   amides derived from fatty acids;   hydrophobic acrylate/vinyl pyrrolidone diblock copolymers;   linear or branched ethylene oxide/propylene oxide random or block copolymers;   sorbitan esters;   ethoxylated alcohols;   ethoxylated alkyl phenols   ionic surfactants;   zwitterionic surfactants;   polymeric emulsifying surfactants;   
       or mixtures thereof. 
     
     
         6 . The formulation of  claim 1 , wherein the surfactant (b) comprises a mixture of fatty acids. 
     
     
         7 . The formulation of  claim 1 , wherein the concentration of surfactant (b) ranges from 0.5 to 20% by weight. 
     
     
         8 . The formulation of  claim 1 , wherein the oil (c) comprises an organic oil, a mineral oil, a vegetable oil, or mixtures thereof. 
     
     
         9 . The formulation of  claim 1 , wherein said the oil (c) comprises saturated or unsaturated fatty acids, saturated or unsaturated fatty acid esters, organic solvents, paraffinic mineral oils, naphthenic oils, palm oil, rapeseed oil, linseed oil, sunflower oil, or mixtures thereof. 
     
     
         10 . A method of manufacturing a formulation according to  claim 1 , wherein said compound (a), said surfactant (b), and said aromatic oil (c) are mixed together. 
     
     
         11 . A method of treating a subterranean formation, comprising injecting into said formation a formulation according to  claim 1 . 
     
     
         12 . The method of  claim 11 , wherein said formulation is injected into said formation by an injection well and/or by a production well. 
     
     
         13 . (canceled) 
     
     
         14 . A water-in-oil emulsion comprising a continuous phase which comprises an aromatic oil and wherein the water/oil interface is at least partially covered with a polyurea-type polymer obtained by hydrolysis and condensation of a compound comprising at least two isocyanate functional groups and wherein said aromatic oil is capable of dissolving said compound comprising at least two isocyanate functional groups and a surfactant. 
     
     
         15 . A method of manufacturing the water-in-oil emulsion of  claim 14 , wherein a liquid oil formulation is brought into contact with an aqueous medium, said formulation comprising:
 (a) a compound comprising at least two isocyanate functional groups;   (b) a surfactant; and   (c) an aromatic oil capable of dissolving compounds (a) and (b).   
     
     
         16 . The formulation of  claim 1 , wherein at least one of said isocyanate functional groups in said compound (a) is blocked. 
     
     
         17 . The formulation of  claim 3 , wherein compound (a) is a diisocyanate trimer. 
     
     
         18 . The formulation of  claim 17 , wherein compound (a) is a isophorone diisocyanate trimer or a hexamethylene diisocyanate trimer. 
     
     
         19 . The formulation of  claim 5  wherein said fatty acids are in their acid form or in a form completely or partially neutralized by a base soluble in said oil. 
     
     
         20 . The formulation of  claim 1 , wherein said formulation is adapted to form a water-in-oil emulsion when contacted by an aqueous medium. 
     
     
         21 . The method of  claim 11 , further comprising contacting an aqueous medium in the subterranean formation with said formulation, wherein the formulation and the aqueous medium form a water-in-oil emulsion comprising a water/oil interface, wherein the water/oil interface is at least partially covered with a polyurea-type polymer resulting from hydrolysis and condensation of the compound comprising at least two isocyanate functional groups.